A Tainted Legacy: The Environmental Impacts of CBRN Agents

“Man has lost the capacity to foresee and forestall. He will end by destroying the Earth”-Albert EinsteinThe deterioration of the biological and physical environment which sustains and supports human life can be traced to the myriad of technical innovations, industrial development, and other activities of humankind, including military operations, such as the research, development, production and deployment of chemical, biological and nuclear weapons. War, and preparations for war, have left an environmental legacy that continues to affect global ecosystems and public health.

Similarly, the release of weaponized agents as weapons of terror, such as the October 2001 mailborne attacks utilizing a military strain of Bacillus anthracis have led to re-thinking the environmental health aspects of CBRN attacks, including containment, air filtration systems, environmental monitoring and surveillance, and decontamination. This also generates secondary environmental concerns, such the toxic effects of decontamination agents, and the disposal of chemical, biohazardous or radiological wastes. In essence, mitigation strategies can lead to secondary environmental contamination.

Much has been learned about the complex interrelationships of living organisms, ecosystems and the human health ramifications of environmental contamination by both planned and unplanned releases into the environment. For example, the noted ecologist George Woodwell, Ph.D of the Woods Hole Oceanographic Institute, and formerly the US Atomic Energy Commission’s Brookhaven National Laboratory, was able to model the actual effects of ionizing radiation on an experimental conifer forest by placing a Cobalt-60 source in the center of a stand of conifer trees and allowing the trees to be irradiated. As a result of radiosensitivity, a demarcated “zone of effect” was shown by dead and dying trees closest to the source, which were then replaced by more radioresistant brush. This demonstrated ecological succession by a hardier life form.

As the Cold War accelerated in the 1950’s and 1960’s, so did the above ground, atmospheric testing of nuclear weapons causing contamination of agricultural lands and, subsequently milk for human consumption. The open-air and underwater nuclear tests of the Cold War era in the Pacific atolls, for example, contaminated marine ecosystems, island terrain and generated an increased mortality rate from cancer among US Navy veterans, and adversely affected the social and physical health of many indigenous populations.

The biogeochemical cycles of our ecosystems received radioactive fallout containing such radionuclides as strontium-90 and Iodine-131 that found their way into the skeletal systems and thyroid glands of so-called “Downwinders” via exposure pathways, such as ingestion of contaminated milk from cows grazing on contaminated fields or inhalation of radioactive particles.

The research, development and production of nuclear weapons have left a radioactive and toxic legacy in many areas of the world, particularly in the former Soviet Union’s “Atomic Cities” ,and, of course, in the US at various Department of Energy facilities, such as the Hanford reservation in Washington State, and various national laboratories, eg., Oakridge National Laboratory, Brookhaven National Laboratory. Many of these contaminated sites are virtually “living laboratories” for toxic chemical and radiological effects on environmental systems and human health.

The processes of disarmament and demilitarization also pose significant risk to both ecological and public health. For example, the dismantling and disposal of nuclear weapons has led to environmental contamination. Overall, the US alone has dismantled well over 60,000 warheads since the 1940s, with the most toxic radioactive element, plutonium, possessing a half-life of 24,000 years, posing an extreme environmental hazard.

It is appropriate to mention the use of depleted uranium (DU) encased projectiles in the discussion on radiological contamination of the environment, which although, are essentially, conventional armor-piercing ammunition (shells), they pose a significant radiological hazard due to the uranium content. Uranium is a dense material, which enhances the ability of projectiles to penetrate armor, and which is also pyrophoric and bursts into flame upon impact. DU is both radioactive and extremely toxic, and routes of exposure include ingestion, inhalation, and other pathways, and results in both alpha particle irradiation and renal toxicity when incorporated. DU-encased shells were used by the US during the 1991 Persian Gulf War and Gulf War II, and the war in Kosovo; similar shells were used by the UK in Gulf War II.

In addition, the scuttling of naval reactors and disposing of barrels of high-level wastes into the marine environment, as well as the wastes of commercial nuclear power generating stations and abandoned uranium tailings seeping into aquatic systems all pose significant threats to environmental health and safety. It is no wonder why ionizing radiation is, by far, the best studied environmental hazard and that these sites and processes can provide modeling for both chemical and radiological releases into the environment.

While nuclear-radiological impacts on the environment and public health are serious, and have long-term consequences, chemical warfare agent research, development, use, manufacture, storage, disposal and, demilitarization of chemical weapons also pose unique threats to the environment and populations. The potential for toxic exposures exists not only for warfighters and non-combatants in wartime, but also for workers involved in the development, production, transport, or storage of chemical armaments and for communities living near these facilities.

One cannot discuss the ecological and health hazards of chemical agents without mentioning the use of the defoliant Agent Orange during the Vietnam War, or the toxic battlefield of the Persian Gulf War, both causing profound environmental damage and adverse health effects among US and Allied military personnel and indigenous populations.

The Chemical Weapons Convention (CWC), which went into effect in 1997, prohibits all development, production, acquisition, stockpiling, transfer, and use of chemical weapons. It requires each nation to destroy its chemical stockpiles, production facilities, and any chemical weapons it may have abandoned in another nation. The Organization for the Prohibition of Chemical Weapons (OPCW) ensures the implementation of the provisions of the CWC.

Chemical demilitarization requirements have provoked much concern regarding the appropriate disposal methodologies, such as incineration vs. chemical neutralization, as well as human health effects and environmental safety.

The chemical demilitarization processes include hydrolysis, microbial degradation, oxidation, and photolysis. Incineration/combustion and vitrification are also demilitarization and disposal processes for CWAs. In terms of ecotoxicity and human health impacts, those chemical warfare agents (CWAs) with known environmental persistence and high grade toxicity pose the greatest hazard profiles. With the exception of the sulfur mustards, (eg, HD), and VX nerve agent, most other CWAs tend to be non-persistent because they are subject to a variety of abiotic and biodegradation processes. Persistent agents are those with low vapor pressure, low water solubility and low rates of abiotic (eg. oxidation) or biotic (eg, bacterial) degradation. The degradation by-products which tend to be the most environmentally persistent, include thiodiglycol for HD; Lewisite oxide for Lewisite; and ethyl methyl phosphonic acid, methyl phosphonic acid, and possibly S-(2-diisopropylaminoethyl) methylphosphonothioic acid (EA 2192) for VX. Lewisite oxide and EA 2192 demonstrate high mammalian toxicity. Other “lesser persistent “agents are the “G”-agents: tabun (GA),sarin (GB),and soman (GD).and their associated degradation by-products. For those agents such as sarin, which possesses the highest vapor pressure and volatility of all of the nerve agents, volatilization is a prime mechanism for transfer in environmental media, eg. from soil and water to air.

While this cannot serve as a treatise on the subject, we need to understand that the biogeochemical mechanisms and cycles of our complex ecosystems can concentrate, magnify and distribute CBRN agents and their precursors and by-products to cause profound environmental harm and subsequent adverse health effects to the ultimate consumers, human populations. Radionuclides can be transported atmospherically to deposit and attenuate on soil, vegetation, aquatic systems and food supplies, and they can be inhaled and retained within the lung. CWAS and their by-products can demonstrate environmental persistence and be toxic to various life forms, as well as human populations. Biological warfare (BW) or bioterrorism agents, including anti-crop and anti-livestock diseases, as well as genetically modified organisms (GMOs) can infect various animals and plants, and may persist on environmental surfaces for extended periods of time, as well as cause infectious diseases in humans. Biodefense research facilities may have highly select agents breach containment.

Newer methods of environmental remediation and protective countermeasures must be sought, not just for demilitarization operations of toxic, biological or nuclear-radiological weapons, but for incidents involving weaponized agents of terror and catastrophic technological failures.

The enforcement of counter-proliferation treaties and other actions to detect and deter rogue nation-states and terrorist factions from acquiring technologies applicable to CBRN development and deployment continue to be priorities to assure global health and security.